iRhythm Holdings discloses a material cybersecurity incident

What the filing says

On June 8, 2026, iRhythm Holdings, Inc. (the "Company") identified unauthorized activity involving data maintained on certain third-party-hosted business applications. The Company promptly activated its cybersecurity response plan and launched an investigation with the support of external advisors and cybersecurity experts to assess and contain the threat. On June 9, 2026, the Company received communications from a threat actor claiming to have obtained sensitive information, including proprietary data, patient protected health information and other personal information.